Pleistocene to Holocene volcanism in the Canadian Cordillera

Abstract

The Canadian Cordillera hosts numerous Pleistocene and Holocene volcanoes and volcanic deposits, including a number that have erupted within the last several hundred years. The nature and composition of volcanic edifices and deposits are diverse and dictated by the complex configuration of tectonic plates along the western margin of British Columbia and the thermal structure of the underlying mantle. Our modern knowledge of these is built upon more than a century of field- and increasingly, laboratory-based studies. We recognize five distinct volcanic domains within the Cordillera that are distributed across British Columbia, the Yukon Territory, and easternmost Alaska. These include: the Wrangell Volcanic Belt (WVB), the Northern Cordilleran Volcanic Province (NCVP), the Anahim Volcanic Belt (AVB), the Wells Grey - Clearwater Volcanic Field (WGCVF) and the Garibaldi Volcanic Belt (GVB) representing the northern extension of the Cascade Volcanic Arc. Volcanism in the Canadian Cordillera spans the full range of explosive to effusive behaviours, encompasses the suite of common volcanic chemical compositions (alkaline to calc-alkaline, nephelinite to peralkaline rhyolite), and is expressed by long-lived stratovolcanoes, shield volcanoes, and calderas, as well as shorter-lived tephra cones and associated lava flows. The range in tectonic settings (subduction to extension), eruption environments (subaerial-subaqueous-cryospheric), and topographic variability make volcanism within the Canadian Cordillera as diverse as anywhere on Earth, yet it is also the least studied. Here, we summarize the current state-of-knowledge concerning volcanism within the Canadian Cordillera and conclude with thoughts on research areas that merit further effort, namely glaciovolcanism and volcanic hazards.